Yamaha WaveRunner VXR VX1800A, Service Manual

Page: 226 / 318

7-19
Control system
1. Connect the YDIS to display “TPS 1”,
“Throttle valve opening angle”, and “TPS
2”.
TIP:
When checking the TPS using the YDIS, do
not start the engine.
2. Squeeze the throttle lever “1” slowly and
check that the displayed throttle valve
opening increases.
3. Check the TPS 1 output voltage and throt-
tle valve opening angle at the fully closed
position “A”.
4. Check the TPS 2 output voltage and throt-
tle valve opening angle at the fully open
position “B”.
TIP:
Operate the throttle lever “1”, and then check
the TPS 2 output voltage and throttle valve
opening angle at the fully open position “B”.
5. Operate the throttle lever so that the TPS
2 output voltage is 4.5 V or less, and then
check the voltage difference between TPS
1 and TPS 2. Measure the TPS input volt-
age if out of specification.
Example:
If the TPS 1 output voltage is 2.5 V and the
TPS 2 output voltage is 4.5 V, then 4.5 -
2.5 = 2.0 V.
6. Disconnect the ETV coupler “a”.
7. Supply power to the ECM, and then mea-
sure the input voltage at the ETV coupler
terminals (wire harness end). Check the
TPS circuit continuity if out of specification.
a. Throttle stop screw nut
b. Throttle stop screw
c. ETV coupler (throttle body end)
TPS 1 output voltage with the throttle le-
ver fully closed
0.45–0.55 V
Throttle valve opening angle with the
throttle lever fully closed
2–8°
c
a
b
TPS 2 output voltage with the throttle le-
ver fully open
4.60–4.70 V
Throttle valve opening angle with the
throttle lever fully open
More than 70°
TPS output voltage difference
1.9–2.1 V
1
B A
1